Growing efforts are being made to develop electric automobiles including fuel cell vehicles and hybrid vehicles. Some of the electric vehicles are capable of selectively supplying electric power from a plurality of power supplies to a drive motor and of selectively charging the power supplies with regenerated electric power from the drive motor {see Japanese Laid-Open Patent Publication No. 2005-237064 (hereinafter referred to as “JP2005-237064A”)}. According to JP2005-237064A, when the vehicle is propelled in a power mode, some batteries whose voltages are equal to or higher than a certain voltage are selected from a plurality of batteries (14), and one of the selected batteries which has the lowest voltage is selected and used (see FIG. 2, paragraphs [0031] through [0041]). When the vehicle is traveling in a regenerative mode, one of the batteries which has the lowest remaining battery level is selected and charged (see FIG. 4, paragraphs [0042] through [0050]).